To explore the effect of DOX on autophagy and the role of autophagy in chemotherapeutic drug resistance of HCC cells, we first detected the autophagy-related proteins Beclin 1, LC3-II, and p62, which are reliable markers of autophagy (36), in BEL-7402 and SMMC-7721 cells treated with various concentrations DOX for the indicated periods. The gene discussed is BECN1; the disease is hepatocellular carcinoma.